U.S. House of Representatives Speaker John Boehner said on Tuesday that prospects were good for passage of a permanent fix to Medicare's flawed doctor-pay formula, a move that would spare physicians from impending pay cuts.

The Republican leader said the House was intent on avoiding another short-term repair like the ones resorted to previously.

A letter signed by 367 U.S. House members to President Barack Obama highlights what they describe as “grave and urgent issues” relating to negotiations to rein in Iran’s nuclear ambitions.

The letter, dated March 20 and released Monday by the House Foreign Affairs Committee, cites concern about the size of Iran’s uranium enrichment program, its lack of cooperation with international inspectors and the need for an intrusive inspection regime.

One of America’s most powerful and outspoken opponents of climate change regulation received election campaign contributions that can be traced back to senior BP staff, including chief executive Bob Dudley.

Jim Inhofe, a Republican senator from Oklahoma who has tirelessly campaigned against calls for a carbon tax and challenges the overwhelming consensus on climate change, received $10,000 (£6,700) from BP’s political action committee (PAC).

Sen. Barbara Boxer (D-Calif.) said she recieved a copy of the chemical reform bill that Sens. Tom Udall (D-N.M.) and David Vitter (R-La.) introduced last week by email that proves the legislation was created by the chemical industry.

"It was clear from the computer coding that the final draft originated at the American Chemical Council itself,” she said.

Her comments come a day before the Senate Environmental and Public Works Committee is expected to discuss the legislation at a hearing.

Republican Rep. Aaron Schock of Illinois, dogged by irregularities in his campaign finance and congressional spending accounts, suddenly announced on Tuesday that he would resign his House seat at the end of the month.

"I do this with a heavy heart," Schock said in a statement.

He said he had given the people of his Peoria-area district his all since his election in 2008, "but the constant questions over the last six weeks have proven a great distraction that has made it too difficult for me to serve the people of the 18th District with the high standards that they deserve and which I have set for myself."